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  1. #1
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    Brompton: singlespeed to multi?

    Hi, folks: Suppose I was (were?) to buy a singlespeed Brompton. Any reason why I couldn't convert it to a gearie down the road with the appropriate hub/shifters? If I'm overlooking something I'd rather know now. Thanks!

  2. #2
    Banned. folder fanatic's Avatar
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    I have converted a Dahon single speed to a 3 speed internal hub. It can be done with relative ease if your bike is a steel frame bike. Aluminum frames are iffy at best.
    Much more information here: http://sheldonbrown.com/frame-spacing.html. I used this article myself when I was in the process of converting my own folding bike.

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    There are many options for a geared Brommie. You could do 3-, 5-, or 8- speed.

  4. #4
    coprolite fietsbob's Avatar
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    newer ones have the mount for the speed shifter for 2 or 6 speed .

    Outside of theirs, A sachs/sram 3by2, & 2 Sturmey Archer offerings,
    other IGH can be fitted,
    but you need to have your mechanic's chops up to the task.
    Last edited by fietsbob; 01-22-12 at 02:31 PM.

  5. #5
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    Every factory Brompton uses the same frame with different components, forks and/or swingarms.

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    Speed Uno
    Dawes Kingpin 2speed

  7. #7
    cycleheaven
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    The single speed Brompton wheel has the same hub that is used for the 2-speed. So you could change to a 2-speed by purchasing two cogs, the dearilleur, 2-speed chain tensioner, shifter and cable kit. You'll probably also need a longer chain.

    Going to a 3 or 6-speed will also require a new wheel and the appropriate tensioner/shifter/cables, etc.

    Brompton offers some of these parts together as upgrade kits.

    One of the great things about Brompton is that they make so many parts available to do things like gearing changes/upgrades. However, it can be expensive and mechanically non-intuitive (if not difficult) if you're not used to working on Bromptons. Be sure to check with a dealer before you get started with a gearing change, unless you're confident you know everything such a project would entail.

    Best of luck.

  8. #8
    Senior Member kamtsa's Avatar
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    You can find here all the brompton parts you may need (use check boxes on the left for more parts). They ship internationally.

    http://www.sjscycles.co.uk/brompton-...ey=cat&cat=758

    There are also third party gearing kits like this http://www.kinetics-online.co.uk/html/8-speed.shtml
    Happier than a camel on wednesday.

  9. #9
    Senior Member bhkyte's Avatar
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    Quote Originally Posted by rcnute View Post
    Hi, folks: Suppose I was (were?) to buy a singlespeed Brompton. Any reason why I couldn't convert it to a gearie down the road with the appropriate hub/shifters? If I'm overlooking something I'd rather know now. Thanks!
    Might be stating the obvious to the OP but.....

    Bromptom has a non standard rear axle width
    Frame needs a 112mm approx hub compared to standard 135mm.
    Upgrades thefore need to use a narrow compactable hub, there are a few internal geared hubs in this size.

    Just checking
    Dual drive Mezzo (GOLD), Dual Drive Mezzo with bullbars (black), White Brompton thingy with Dahon Androes stem and bull bars. Birdie (old sytle) 7 speed. Downtube NS8. Birdie red.

  10. #10
    coprolite fietsbob's Avatar
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    There are retrofits of the SA 8 speed , requires pulling a bunch of spacers
    off the axle , left side I suppose.
    I think Kinetics, a shop in Scotland offers a kit made up of TW made SA parts,
    hub and a small chainring crankset.

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